A Compact Printed UWB MIMO Antenna with Electronically Reconfigurable WLAN Band-Notched Characteristics

In this research paper, a simple design of an ultra-wideband (UWB) multi-input multi-output (MIMO) antenna with low envelope correlation coefficient (ECC), high isolation, enhanced gain, radiation efficiency and reconfigurable band notching functionality is proposed. Two symmetrical slots are carefully integrated into the partial ground plane of the conventional monopole to provide a notched band at 5.8[Formula: see text]GHz for the WLAN system. This notching method is simple and does not endure negative effect performance or any design complexity. The notched band is then controlled using PIN diodes. A complete biasing circuit is integrated on the same partial ground plane to bias the PIN diodes in forward and reverse directions. To reduce the complexity of the design that may be increased due to the reconfiguration circuit, isolation enhancement is accomplished by orthogonal placement of the elements rather than using any additional decoupling structures. A prototype of the MIMO UWB structure is fabricated and its performance parameters are experimentally tested. The captivating agreement between simulation and measurement demonstrates that the proposed antenna system is a good candidate for UWB applications with an operating band extending from 3 to 11[Formula: see text]GHz, notch-band reconfiguration freedom, and isolation of more than 20[Formula: see text]dB.

Kuznets curve with parabola-shaped ultra-wideband antenna with defected ground plane for communications

Purpose This paper aims to state the configuration of the proposed antenna which is competent to many networks such as LTE and X band applications. The experimental study encountered the significance of the proposed antenna. Design/methodology/approach A novel compact Kuznets curve with parabola-shaped quad-band notched antenna is demonstrated in this paper. The presented prototype is ascertained on a composite material composed of woven fiberglass cloth with an epoxy resin binder. The resulting ultra-wideband antenna ranges 3.1–3.54 GHz, 5.17–5.51 GHz, 5.74–6.43 GHz and 6.79–7.60 GHz. To avoid the frequency bands which cause UWB interference,the projected antenna has been incorporated with slotted patch. The proposed antenna design is attained in four steps. The simple circular patch antenna model with defected ground plane is subjected to stepwise progression by including parabola-shaped slot and U shaped slot on the patch to attain four notched bands. Findings This projected antenna possesses an optimal bond among simulated and measured outcomes,which is more suitable for the quad notched band applications. Substrate analysis is done by varying substrate material, and notch behavior is presented. The proposed method’s optimum performance in metrics such as return loss, voltage standing wave ratio and radiation pattern varies its frequency range from 2.56 to 7.6 GHz. Originality/value The antenna adaptation of the defected ground plane has achieved through the quad notched band with operating frequency ranges 2.56 to 7.6 GHz and with eliminated frequency ranges 3.55–5.16 GHz, 5.52–5.73 GHz, 6.44–6.78 GHz and 7.66–10.6 GHz.

Cuboidal quad-port UWB-MIMO antenna with WLAN rejection using spiral EBG structures

This study presents a novel configuration of a cuboidal quad-port ultra-wideband multiple-input and multiple-output antenna with WLAN rejection characteristics. The designed antenna consists of four F-shaped elements backed by a partial ground plane. A 50 Ω microstrip line is used to feed the proposed structure. The geometry of the suggested antenna exhibits an overall size of 23 × 23 × 19 mm3, and the antenna produces an operational bandwidth of 7.6 GHz (3.1–10.7 GHz). The notched band characteristic at 5.4 GHz is accomplished by loading a pair of spiral electromagnetic bandgap structures over the ground plane. Besides this, other diversity features such as envelope correlation coefficient, and diversity gain are also evaluated. Furthermore, the proposed antenna system provides an isolation of −15 dB without using any decoupling structure. Therefore, to validate the reported design, a prototype is fabricated and characterized. The overall simulated performance is observed in very close agreement with it's measured counterpart.

Realizing UWB Antenna Array with Dual and Wide Rejection Bands Using Metamaterial and Electromagnetic Bandgaps Techniques

This research article describes a technique for realizing wideband dual notched functionality in an ultra-wideband (UWB) antenna array based on metamaterial and electromagnetic bandgap (EBG) techniques. For comparison purposes, a reference antenna array was initially designed comprising hexagonal patches that are interconnected to each other. The array was fabricated on standard FR-4 substrate with thickness of 0.8 mm. The reference antenna exhibited an average gain of 1.5 dBi across 5.25–10.1 GHz. To improve the array’s impedance bandwidth for application in UWB systems metamaterial (MTM) characteristics were applied it. This involved embedding hexagonal slots in patch and shorting the patch to the ground-plane with metallic via. This essentially transformed the antenna to a composite right/left-handed structure that behaved like series left-handed capacitance and shunt left-handed inductance. The proposed MTM antenna array now operated over a much wider frequency range (2–12 GHz) with average gain of 5 dBi. Notched band functionality was incorporated in the proposed array to eliminate unwanted interference signals from other wireless communications systems that coexist inside the UWB spectrum. This was achieved by introducing electromagnetic bandgap in the array by etching circular slots on the ground-plane that are aligned underneath each patch and interconnecting microstrip-line in the array. The proposed techniques had no effect on the dimensions of the antenna array (20 mm × 20 mm × 0.87 mm). The results presented confirm dual-band rejection at the wireless local area network (WLAN) band (5.15–5.825 GHz) and X-band satellite downlink communication band (7.10–7.76 GHz). Compared to other dual notched band designs previously published the footprint of the proposed technique is smaller and its rejection notches completely cover the bandwidth of interfering signals.

Coplanar Waveguide-fed UWB Slotted Antenna with Notched-band Performance

Compact coplanar waveguide Ultra-wideband (UWB) monopole antenna with band notched characteristics is presented in this paper. The band rejection is achieved by etching a circular slot on the radiating patch. The antenna is printed on the FR4-Epoxy substrate with overall dimensions of 23.5 × 31 × 1.5 mm3. The measured results indicate that the antenna operates in the frequency range from 1.76 to 11.07 GHz and rejects the band 2.42 to 5.37 GHz with an acceptable measured input impedance over the whole operating frequency bandwidth. Furthermore, the simulated results indicate that the antenna exhibits stable radiation patterns with appreciable gain and efficiency over the whole operating band except at the notched-band. Accordingly, this antenna provides a good solution for wireless communication systems with good characteristics.

Planar microstrip UWB bandpass filter with quad notched bands and high selectivity

Background: Aiming at solving the problems of large design size and insufficient number of notched band for traditional ultra-wideband (UWB) filters, a planar compact microstrip UWB bandpass filter (BPF) with quad notched bands and good selectivity is proposed using a modified multiple-mode resonator (MMR) and defected ground structure (DGS). Methods: The MMR consists of a stepped impedance stub above and two pairs of open-circuited stubs on both sides, which c an generate the passband and double notched bands of UWB filter, the other two notched bands are obtained by DGS. Results: The UWB filter with quad notched bands respectively centered at 3.9GHz, 5.7GHz, 7.9GHz, and 9.8GHz is fabricated and measured. Conclusion: The measured results are basically consistent with the simulated results, which proves the correctness and practicability of the UWB filter.